So what will happen if Nintendo lose? Where will the money go to or is these any money at all?
In a typical class action the money ordered to be paid gets put into a holding account/escrow account upon them losing (what might go for any appeals varies a bit).
At that point those that might have either initiated the lawsuit or bought in later will tend to be notified, everybody else that might be affected* gets told to visit a website, call a number, send a letter to... and put in a claim. There might also be lawyers offering services to claim it back for you; anybody that visited the UK for years probably saw half a hundred adverts for someone offering to get back PPI for them**. Likewise advocacy groups might be able to help you with a claim.
There is generally said to be some duty of care to advertise things, though in practice this might well just mean advert in a dead tree paper and magazine that nobody reads any more and hope others pick it up. Various websites, usually tied to law firms, advocacy groups or similar interests, also take note of what they can
https://www.classaction.com/settlements/
https://www.consumer-action.org/lawsuits/
After a certain amount of time this pool will close (you might see adverts saying time is running out) and no more claims can be made.
*for tech stuff it can come down to having serials within this range, even if others are affected by the same issue. Don't know what goes with this one, and arbitration may narrow it further still if the case can not demonstrate for a given range and they did tweak something -- the HP-Nvidia laptops one a few years being a fun example as pretty much anybody fixing laptops in that timeframe will tell you Nvidia chips in ones (not just the ones in question) of that vintage are going to die. Depending upon what you have it might only be a very small sum (again those that initiated and later bought in tending to get more) but up to you.
**payment protection insurance. If you were one of the people in the world that takes out loans then the banks cooked up a scheme to get people to buy insurance in case they could not make a repayment one month. Ultimately this was deemed wrong and ordered to be repaid.
I should probably also note there are often very few initial checks on claimants, however if you claim falsely, intentionally or through ignorance, then expect serious serious repercussions on that one (obviously intentionally defrauding is worse than ignorance but the latter is not going to see you getting to keep things, which if you have already spent it...). To that end read any instructions that come with it.